Printing calculating machine



March 22, 1 o. J. SUNDSTRAND PRINTING CALCULATING MACHINE 2 Sheets-Sheet1 Original Filed Jan. 14, 1954 o. J. SUNDSTRAND 2,929,476 PRINTING)CALCULATING MACHINE March 22, 1960 2 Sheets-Sheet 2 Original Filed Jan.14, 1954 United States Patent C PRINTING CALCULATING MACHINE Oscar J.Sundstrand, West Hartford, Conn., assignor to Victor Adding Machine Co.,Chicago, Ill., a corporation of Illinois Original application January14, 1954, Serial No. 404,088. Divided and this application July 18,1957, Serial No. 672,804

3 Claims. (Cl. 192-28) ,The invention relates generally to onerevolution clutch mechanisms, particularly for operation of adding,calculating, check writing, and similar machines. More particularly, itrelates to an improved means for reducing the frictional force opposingrelease of the clutch pawl for engagement with its associated ratchetwheel.

. This application is a division of my copending application Serial No.404,088, filed January 14, 1954, entitled Printing Calculating Machine.

It is thus an object of the invention to provide an improved mechanismfor reducing the friction opposing release of the clutch mechanism forengagement upon operation of the motor starting and clutching means.

It will be understood that in the design of adding, calculating, andcheck writing machines, it is desirable to reduce, as much as possible,the energy (or force) required to be applied to the control mechanismfor starting operation of the machine, and the present invention isdirected to means for accomplishing this result.

Other objects will become apparent from the follow ing description,reference being had to the accompanying drawings, in which- Fig. l is avertical sectional View, taken from the right, of an illustrativemachine embodying the invention, showing particularly the manuallyoperated control elements for initiating a cycle of operation;

Fig. 2 is a vertical sectional view, from the left side of the machine,broken in parts, showing the particular one revolution clutch mechanismand adjusting means therefor; and

Fig. 3 is a fragmentary horizontal sectional view showing the drivegearing for the one revolution clutch mechanism.

It is a common expedient to utilize as a means for controlling theoperation of an adding, calculating, or check writing machine, toprovide a motor and one revolution clutch mechanism control operated bythe operator upon depression of a motor control bar or key, and it isdesirable that the force required for the depression of such key be verylight; This desiderata is emphasized if the machine is to beautomatically controlled, because under these conditions the entiremechanism for operating the motor starting and one revolution controlclutch is operated by a train of mechanism, the parts of which mustnecessarily be strengthened, if the force required to disengage theclutch mechanism and start the operation of the motor is more thanabsolutely required.

In the present application, the means for initiating operation of theone revolution clutch mechanism and causing the energization of thedriving motor, is shown in Fig. 1, the mechanism being more or lessconventional to machines of the type to which reference has been made.

Referring to Fig. 1, a motor bar 50 (which, upon depression, controlsthe initiation of an operating cycle) ICC is provided with a key stem480 suitably guided by studs 482 for substantially vertical movement.This key stem operates against the tension of the spring 484, one end ofwhich is suitably anchored to the frame of the machine and the other endof which is connected to an ear 496 forming part of the key stem 480.The ear 496 overlies a stud 498 on a lever 500 pivoted upon stud 502secured to the frame of the machine, and the rearward end of this lever500 carries a stud 504 cugageable in an open slot 506 formed in the endof a lever 508. The rearwardly projecting arm of lever 508 overlies aroller stud 510 carried by a vertically reciprocable link 512 guided bya stud 516 extending through a suitable slot in the link 512. The lowerend of the link 512 carries an insulating washer 514 for cooperationwith the blade of a motor energizing switch 176. This disc 514 ispreferably mounted eccentrically so that it may be readily adjusted forsuitably timed operation in conjunction with the one revolution clutchmechanism.

The link 512 is urged upwardly by a suitable tension spring connectedbetween this link and a stud 518, or, stated conversely, an arm 520secured to a shaft 523 by a screw 524 is urged to swing clockwise by thetension spring whenever the lever 512 is depressed.

From the foregoing, it will appear that when the motor bar (orcomparable means) is operated to cause initiation of a cycle ofoperation of the machine, the kinematic train comprising the arm 496 ofits key stem 482, levers 500 and 508, will result in depression of thelink 512 and through its associated spring attached to stud 518 willtend to swing clockwise (Fig. l) the arm 520, its associated shaft 523,and its screw 524, in addition to closing the switch 176 to energize thedriving motor.

Referring to Fig. 2, the shaft 523 has an arm 528 secured thereto sothat when the motor bar 50 is depressed and the shaft 523 turnedclockwise (Fig. 1) the arm 528 will swing counterclockwise from theposition in which it is shown in Fig. 2. The end of the arm 528 has apin and open end slot connection to the forwardly extending arm 530 ofthe three-arm tripping lever 532. This arm 530 carries a stud 531engageable with a spring pressed detent lever 533 which is provided withsuitable surface for engagement with the stud 531 so as to hold thelatter in either its operative or inoperative position.

As shown in Fig. 3, the machine is driven by a motor 150, the rotorshaft of which is formed as a pinion 152 meshing with gear 154. Thislatter gear is preferably.

connected by suitable friction means to a pinion 156 which in turnmeshes with the gear 158, having a hub 160 which is rotatable on asuitably mounted shaft 162. The frictional driving connection betweenthe gear 154 and pinion 156 is more or less conventional, being providedto form a part of the driving connection between the motor and themachine parts operated thereby under all normal conditions of operation,permitting the frictional connection to yield if there is any abnormallockup of the machine.

A ratchet wheel 178 is fixed to the hub 160. A plate cam disc 182 issupported for rotation on the shaft 162. A pawl 180 is pivoted to thedisc 182 and has the tooth thereof urged to move into engagement withthe ratchet wheel 178 by a spring 181, and when thus engaged provides adriving connection between the ratchet wheel 178 and disc 182, rotatingthe latter clockwise (Fig. 2). The pawl 180 is normally held fromengagement with its ratchet Wheel by having the upper portion thereofabut against the toothed end 555 of an arm 534 of the three-arm trippinglever 532. A stud 183 on the disc 182 coacts with the upper rear portionof the pawl 180,

, nection between the ratchet wheel and the disc 132.

as shown in Fig. 2, re positively preclude turning of the disc 182beyond its starting position when the arm'end 555 is in abuttingengagement with the pawl.

The disc 182 has a sidewardly projecting stud 184 to which an actuatingarm 18 6 is pivotally connected, the latter being connected by asuitable' arm to the main shaft 110, to rock the latter hack and forthupon each revolution of the disc 132. v The disc 182 also carries a stud538 which is adapted, shortly before the completion of the operatingcycle, to engage a suitable camming surface on arm 536 of the three-armlever 532 so as to return the three-arm lever 532 to its normal pawlengaging position. I The disc 182 has a sharply rising cam surface 541at its peripheral edge, which is adapted to be en a ed by a roller 543carried at the end of one arm of a bellcran k lever 545 pivoted on astud 547. The roller '543 is resiliently urged into engagement with theedge of the disc 182 by a suitably anchored tension spring 549. Theextent to which the spring 549 my swing the lever 54S counterclockwiseis limited by an eccentric collar 551 secured in adjusted position by ascrew 553. p

In operation, upon depression of the motor be et), as previouslydescribed, the arm 523 (Fig. 2) will be swung counterclockwise and end555 of the arm 534 of the three-arm tripping lever 532 will be raised todis engage it from the pawl 180, whereupon the latter will be swung byits spring 181 into engagement'with the teeth of ratchet wheel =178, andthus form a driving con- The disc 1-82 will therefore be drivenclockwise until the stud '538 thereof engages the cam surface of the arm536 of the three-arm lever 532, shortly before the end of one revolutionof the disc, whereupon the part 555 of arm 534 will be moved intoposition to engage the pawl 1 80 and swing it counterclockwise todisengage it from the ratchet wheel 17 8. Upon completion of onerevolution of the disc 182, the roller 543 will be in engagement withthe cam rise portion 541 and prevent retrograde or counterclockwiserotation thereof, and due to the force applied by the spring 549 to thelever 545, will tend to move the disc 182 clockwise, but the extent ofsuch rotary movement of the disc 182 is limited by the en'- gagement ofthe lever 545 with the eccentric collar 551. As shown in Fig. 2, theeccentric stop 551 is adjusted to terminate movement of the followerroller 543 toward the coacting cam simultaneously with movement of thedisc 182 into its starting position. Thus, there is no tendency torotate the disc 182 beyond the position in which it is shown in Fig. 2,and the tension of the spring 181 is the only force tending to hold thepawl 180 in engagement with the tooth 555 of the arm 534.

If the counterclockwise swinging movement of the lever 545 were notlimited by the eccentric collar 551, the force applied by theresiliently pressed roller 5-43 would increase the friction between thetooth 555 of the arm 534 and the pawl so as to increase the forcerequired to swing the three-arm tripping lever 53?. clockwise uponinitiating the following cycle of operation. The stop position of thedisc 182 is thus precisely adjustable by adjustment of the eccentriccollar'*55=1, but nevertheless no force is applied tending to rotate thedisc clockwise. Thus the only force applied between the pawl 1'80 andthe tooth 555 is that due to the spring 1-81, which may be o-f's'uchstrength as to apply but a very small force tending to swing the pawl136 into engagement with the ratchet wheel 178.

While I have shown and described a preferred embodimeht of my invention,it will be apparent that aniriero'us variations and modificationsthereof may be made without departing from the underlying principles ofthe invention. I therefore desire, by the following claims, to includewithin the scope of the invention all such variations and modificationsby which substantially the results of my invention may be obtainedthrough the use of substantially the same or equivalent means.

I claim:

I. In a business machine, the combination of operating means, a motor, aratchet wheel connected for rotation by said motor in a predetermineddirection, a rotary driven member connected to said operating means andcarrying a clutching pawl biased for engagement with said ratchet wheel,a movable trip element normally engaged abuttingly with a portion ofsaid pawl to disengage the pawl from said ratchet wheel, rigid means onsaid driven member coacting with said pawl and said trip elementpositively to preclude rotation of the driven member in said directionbeyond a predetermined starting position when the trip element is inengagement with said pawl, said driven member defining an arcuate camthereon, a cam follower opposing said cam, a strong spring biasing saidfollower firmly against said cam, the portion of said cam which opposessaid follower as said driven member approaches said starting positionforming an incline oriented in relation to said follower to producefromthe yieldable force of the follower on said incline a reaction onsaid earn which strongly urges said driven member rotatably in saiddirection toward said starting osition, adjustable stop means separatefrom said cam ositioned to ositively terminate movement of said followerin the direction or said cam before the follower has eached thelowermost portion of said incline and simultaneously with movement ofsaid driven member into said starting position, means for fixing saidadjustable stop means in adjusted position, a manual control member, andlinkage means connecting said control member to said trip element toslidably disengage the latterfrom said pawl.

2. In a business machine, the combination of operating means, a motor, adriving clutch comprising a rotary driving member connected for rotationby said motor in a predetermined direction and a rotary driven memberconnected to said operatingmeans, a movable trip element, means on saiddriven member normally coacting with said trip element positively torestrain rotation of the driven member in said direction beyond apredetermined starting position, said driven member defining an arcuatecam thereon, a cam follower opposing said cam, a spring biasing saidfollower firmly against said earn, the portion of said cam which opposessaid follower as said driven member approaches said starting positionforming an incline oriented in relation to said follower to produce fromthe yieldable'force of the follower on said incline a reaction on saidcam which strongly urges said driven member rotatably in said directiontoward said starting position, stop means separate from said campositioned to positively terminate movement of said follower toward saidcam before the follower has reached the lowermost portion of saidincline and simultaneously with movement of said driven member into saidstarting position, a manual control member, and linkage means connectingsaid control member to said trip element to shift the latter forreleasing said driven member for rotation.

3. In a business machine, the combination of operat ing means, drivingmeans including a single revolution clutch comprising a rotary drivingmember therefor and a rotary driven member connected to said operatingmeans" and having a normal direction of rotation, said single revolutionclutch including releasable stop. means coacting' with said drivenmember positively to termihate normal rotation of the latter in an exactstarting position by the abutting action of slidably disengageablc partsforming components of said stop means, a spring biased cam follower,means forming on said driven member an arcuate cam surface opposing saidcam follower and having a steeply inclined portion positioned forengagemcnt by said follower as said driven member approaches saidstarting position thereof and having an orientation relative to saidfollower that produces from the yieldable force of said follower on saidinclined cam portion a reaction on said inclined cam portion whichReferences Cited in the file of this patent UNITED STATES PATENTSVincent July 2, Eames Mar. 14, Lawrence June 16, Russell et al Oct. 13,

